1. Field of the Invention
The present invention relates to an instrument for a vehicle, and more particularly to an instrument mounted on a vehicle showing a measured value using a pointer.
2. Description of the Related Art
Generally, a vehicle is provided with indicator type instruments showing a measured value such as a vehicle speed, an engine speed (RPM) and so forth. Such an instrument comprises: an instrument board provided with graduations and scale marks such as figures, characters, signs or so forth on a surface thereof; a pointer disposed in front of the instrument board; internal parts driving the pointer according to the measured value; and a wiring board provided with a circuit pattern and on which the internal parts are fixed.
In this instrument, sunlight illuminates the pointer and the instrument board so that a vehicle driver visually recognizes the measured value in the daytime. While at night, light from a light source such as a cathode ray tube (CRT) or a light emitting diode (LED) is transmitted through an indicating part of the pointer and scale marks, then launched so that the vehicle driver visually recognizes the measured value. A self-luminous instrument as such is well known in this technical field.
However, just the pointer and the scale marks are illuminated to be seen and the instrument board itself cannot be seen in the above-described self-luminous instrument at night. Thus, there is a problem that even if sticking to design, material and etc., to produce a high-class image of the instrument board itself, an observer cannot recognize it visually.
Therefore, as shown in FIG. 5, it is possible that an LED 3 is provided to illuminate an instrument board 1 and a pointer 2 so that the instrument board 1 itself can be seen as well at night as in the daytime. However, when a point source of light such as LED is used to illuminate the instrument board 1 and the pointer 2, there is a fear that the whole instrument board face may not be illuminated uniformly, a high brightness portion A illuminated with high brightness appearing partially as shown in FIG. 6. In particular, when a high reflective metal is used as the instrument board 1 for having a high-class image, such a phenomenon appears conspicuously.